/*
 * Copyright (C) 2008 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.lib_qrcode.zxing.view;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.Typeface;
import android.graphics.drawable.BitmapDrawable;
import android.util.AttributeSet;
import android.view.View;
import com.google.zxing.ResultPoint;
import com.lib_qrcode.R;
import com.lib_qrcode.zxing.camera.CameraManager;
import java.util.Collection;
import java.util.HashSet;

/**
 * This view is overlaid on top of the camera preview. It adds the viewfinder
 * rectangle and partial transparency outside it, as well as the laser scanner
 * animation and result points.
 *
 * @author dswitkin@google.com (Daniel Switkin)
 */
public final class ViewfinderView extends View {

  private static final int[] SCANNER_ALPHA = {
      0, 64, 128, 192, 255, 192, 128, 64
  };

  private final Paint paint;
  private Bitmap resultBitmap;
  private final int maskColor;
  private final int resultColor;
  private final int resultPointColor;
  private volatile Collection<ResultPoint> possibleResultPoints;
  private volatile Collection<ResultPoint> lastPossibleResultPoints;

  private static final long ANIMATION_DELAY = 10L;
  private static final int OPAQUE = 0xFF;

  private int ScreenRate;

  private static final int CORNER_WIDTH = 8;

  private static final int SPEEN_DISTANCE = 5;

  private static float density;
  private static final int TEXT_SIZE = 13;

  private static final int TEXT_PADDING_TOP = 30;

  private int slideTop;
  private int slideBottom;
  private boolean isFirst;

  // This constructor is used when the class is built from an XML resource.
  public ViewfinderView(Context context, AttributeSet attrs) {
    super(context, attrs);

    // Initialize these once for performance rather than calling them every
    // time in onDraw().
    paint = new Paint();
    Resources resources = getResources();
    maskColor = resources.getColor(R.color.viewfinder_mask);
    resultColor = resources.getColor(R.color.result_view);
    resultPointColor = resources.getColor(R.color.possible_result_points);
    possibleResultPoints = new HashSet<ResultPoint>(5);

    density = context.getResources().getDisplayMetrics().density;
    ScreenRate = (int) (15 * density);
  }

  @Override public void onDraw(Canvas canvas) {
    Rect frame = CameraManager.get().getFramingRect();
    if (frame == null) {
      return;
    }

    if (!isFirst) {
      isFirst = true;
      slideTop = frame.top;
      slideBottom = frame.bottom;
    }
    int width = canvas.getWidth();
    int height = canvas.getHeight();

    // Draw the exterior (i.e. outside the framing rect) darkened
    paint.setColor(resultBitmap != null ? resultColor : maskColor);
    canvas.drawRect(0, 0, width, frame.top, paint);
    canvas.drawRect(0, frame.top, frame.left, frame.bottom + 1, paint);
    canvas.drawRect(frame.right + 1, frame.top, width, frame.bottom + 1, paint);
    canvas.drawRect(0, frame.bottom + 1, width, height, paint);

    if (resultBitmap != null) {
      // Draw the opaque result bitmap over the scanning rectangle
      paint.setAlpha(OPAQUE);
      canvas.drawBitmap(resultBitmap, null, frame, paint);
    } else {

      paint.setColor(getResources().getColor(android.R.color.holo_red_light));
      canvas.drawRect(frame.left, frame.top, frame.left + ScreenRate, frame.top + CORNER_WIDTH,
          paint);
      canvas.drawRect(frame.left, frame.top, frame.left + CORNER_WIDTH, frame.top + ScreenRate,
          paint);
      canvas.drawRect(frame.right - ScreenRate, frame.top, frame.right, frame.top + CORNER_WIDTH,
          paint);
      canvas.drawRect(frame.right - CORNER_WIDTH, frame.top, frame.right, frame.top + ScreenRate,
          paint);
      canvas.drawRect(frame.left, frame.bottom - CORNER_WIDTH, frame.left + ScreenRate,
          frame.bottom, paint);
      canvas.drawRect(frame.left, frame.bottom - ScreenRate, frame.left + CORNER_WIDTH,
          frame.bottom, paint);
      canvas.drawRect(frame.right - ScreenRate, frame.bottom - CORNER_WIDTH, frame.right,
          frame.bottom, paint);
      canvas.drawRect(frame.right - CORNER_WIDTH, frame.bottom - ScreenRate, frame.right,
          frame.bottom, paint);

      slideTop += SPEEN_DISTANCE;
      if (slideTop >= frame.bottom) {
        slideTop = frame.top;
      }
      Rect lineRect = new Rect();
      lineRect.left = frame.left;
      lineRect.right = frame.right;
      lineRect.top = slideTop;
      lineRect.bottom = slideTop + 18;
      canvas.drawBitmap(((BitmapDrawable) (getResources().getDrawable(R.drawable.fle))).getBitmap(),
          null, lineRect, paint);

      paint.setColor(Color.WHITE);
      paint.setTextSize(TEXT_SIZE * density);
      String text = getResources().getString(R.string.scan_text);
      float textWidth = paint.measureText(text);

      canvas.drawText(text, (width - textWidth) / 2,
          (float) (frame.bottom + (float) TEXT_PADDING_TOP * density), paint);

      Collection<ResultPoint> currentPossible = possibleResultPoints;
      Collection<ResultPoint> currentLast = lastPossibleResultPoints;
      if (currentPossible.isEmpty()) {
        lastPossibleResultPoints = null;
      } else {
        possibleResultPoints = new HashSet<ResultPoint>(5);
        lastPossibleResultPoints = currentPossible;
        paint.setAlpha(OPAQUE);
        paint.setColor(resultPointColor);
        for (ResultPoint point : currentPossible) {
          canvas.drawCircle(frame.left + point.getX(), frame.top + point.getY(), 6.0f, paint);
        }
      }
      if (currentLast != null) {
        paint.setAlpha(OPAQUE / 2);
        paint.setColor(resultPointColor);
        for (ResultPoint point : currentLast) {
          canvas.drawCircle(frame.left + point.getX(), frame.top + point.getY(), 3.0f, paint);
        }
      }

      postInvalidateDelayed(ANIMATION_DELAY, frame.left, frame.top, frame.right, frame.bottom);
    }
  }

  public void drawViewfinder() {
    resultBitmap = null;
    invalidate();
  }

  /**
   * Draw a bitmap with the result points highlighted instead of the live
   * scanning display.
   *
   * @param barcode An image of the decoded barcode.
   */
  public void drawResultBitmap(Bitmap barcode) {
    resultBitmap = barcode;
    invalidate();
  }

  public void addPossibleResultPoint(ResultPoint point) {
    synchronized (possibleResultPoints) {
      possibleResultPoints.add(point);
    }
  }
}
